This invention relates to a holding device for brake linings of a disk brake of a road vehicle, in which the disk brake is provided with brake linings and a brake caliper with brake lining shafts, into which a brake lining and, optionally, one pressure distributor plate is inserted, with each brake lining having a lining carrier and lining material. The holding device includes a holding bracket engaging over two of the brake linings that lie opposite one another on both sides of the brake disk, and a prestressed, leaflike lining holding spring supported on the holding bracket and acting on a circumferential face of the lining carrier of each brake lining.
A wide variety of disk brake embodiments for commercial vehicles is known. A lining holding spring that acts on a region of a brake lining assigned to holding bracket (see, for example, international PCT document WO 92/00465 A1) is intended to fix the brake lining within the brake lining shaft and, moreover, to compensate for unavoidable tolerances. The brake lining is pressed into the brake lining shaft by a prestress, and rattling noises are to be reduced or completely eliminated by this arrangement. This arrangement has proven itself effective, but it is still considered to be a disadvantage that the brake material digs into the lining carrier due to unavoidable oscillations. This undesirable property is attributed to the material pairing.
German document DE 10 2004 053 026 A1, European document EP 1 441 141 B1, German documents DE 38 39 957 A1 and DE 1 425 232 A, and U.S. Pat. No. 4,498,564 are also identified as prior art.
One object of this invention is to eliminate the above-described problem using a simple design.
This object is achieved by arranging on the brake lining, in addition to the lining holding spring, at least two lining surround springs that exert a compressive force, at least in sections, on the circumferential face of each brake lining. The lining surround springs are configured in such a way that they cover in each case one edge region of the brake lining carrier, which edge region comprises at least two corner regions of the brake lining. For a lining carrier that has, in essence, only four corner regions, all four corner regions are preferably enclosed by at least one, or two or more, lining surround springs. An embodiment of this type, having two lining surround springs and a lining holding spring, is considered unknown in the prior art.
Therefore, at least one lining surround spring, which exerts a compressive force at least in regions (in the mounted position in the brake) on the circumferential face of each brake lining, is preferably arranged on that brake lining. The lining surround spring can be configured in one piece or multiple pieces.
The lining surround spring is not necessarily a spring which runs around the brake lining carrier by 360° completely or even in one piece. Each lining surround spring preferably encloses at least two of the lining carriers. The lining holding spring and the lining surround springs are preferably “substantially” to run around the lining carrier, that is to say, it or they is or are to cover more than half of the edge regions of the lining carriers.
The lining surround spring preferably comprises a material having a relatively high hardness, such as steel, as a result of which the effect of the lining material digging into the lining carrier is largely reduced.
Moreover, a drop in the degree of efficiency of the disk brake over the service life is also reduced.
The combination of the lining holding spring and the lining surround springs produces an optimized sprung mounting in the brake carrier shaft and/or in the brake caliper shaft, as a result of which the wear of components that are movable relative to one another and noise are reduced.
To avoid corrosion between the brake material and the brake carrier during a relatively long standstill of a road vehicle, the lining surround springs may be produced from a corrosion-resistant steel, and, in particular, stainless steel.
Optimally, the lining surround springs are supported at least on one of the two lateral circumferential faces that lie opposite one another and on one circumferential face of the brake lining that lies opposite the lining holding spring. Here, the regions of the lining surround springs supported on the shorter, lateral circumferential faces cause the brake lining to be supported in the brake lining shaft laterally in a sprung manner.
The spring action is optimized if the regions assigned to the circumferential faces of the lining surround springs are of undulating design, with the result that, in each case, the lining surround spring makes contact with the central regions of the circumferential face.
However, in one alternative form, each brake lining may be assigned two lining surround springs that extend over those lateral circumferential faces of the brake lining, which lie opposite one another, and over the two outer and lateral regions of the brake lining, which lie opposite the lining holding spring. This saves material.
It is also possible to assign the brake lining with only one lining surround spring that extends over the region outside the lining holding spring. The lining holding spring in this embodiment should also make contact with at least the central regions of those lateral faces of the brake lining which lie opposite one another. The region which lies opposite the lining holding spring can be designed in such a way that the lining surround spring makes contact with at least the lateral regions. Moreover, it is also possible to have the lining surround spring make contact only with the central region of the face which lies opposite the lining holding spring. It is also conceivable for the lining surround spring to make contact with both the lateral regions and the central region of that face of the brake lining which lies opposite the lining holding spring.
As an alternative, the lining holding spring and the lining surround spring can be configured as an integral shaped part. This embodiment makes a progressive characteristic curve possible for the lining holding spring and, as a result, permits load-dependent suspension.
Furthermore, depending on the requirements and circulating distance, the lining surround spring or the lining surround springs can be fixed positively on the respective brake linings.
In an embodiment with one lining surround spring, the end regions assigned to the lining holding spring can be angled away to the outside or can engage behind an angled-away tab of the lining carrier.
If an embodiment is equipped with two lining surround springs, the ends which face the lining holding spring are likewise angled away to the outside and engage behind the angled-away tabs of the lining carrier.
The other ends of the lining surround springs, which lie opposite the lining holding spring, are of eyelet-shaped design and engage in recesses or in tapered sections of the brake lining. This also achieves positive fixing.
In a particularly advantageous way, each lining surround spring is configured as a flat or leaf spring, in relation to the cross section.
One embodiment of the invention will be described in greater detail using the appended drawing.